President Barack Obama watches as Joey Hudy (L), 14, from Phoenix, Arizona pumps the Extreme Marshmallow Cannon he invented, while touring student science fair projects on exhibit in the State Dining Room at the White House February 7, 2012 in Washington, DC. Obama hosted the second White House Science Fair celebrating the student winners of science, technology, engineering and math (STEM) competitions from across the country. (Photo by Molly Riley-Pool/Getty Images)

An Israeli soldier of the Caracal battalion smiles during a 23-kilometer march marking the end of their training in Israel's Negev desert, near Kibbutz Sde Boker February 14, 2013. The “Caracal” battalion, two-thirds of whose members are women, was established in 2004 with the purpose of incorporating female soldiers in combat units. The main mission of Caracal is routine patrols on Israel's border with Egypt to intercept infiltrators and smuggling from the Sinai desert. (Photo by Darren Whiteside/Reuters)

Women sing and dance as children gather in the background during the so-called parade of children's troops in Rostov-on-Don, southern Russia, May 14, 2015. About 500 children aged from 4 to 10, members of youth military patriotic clubs, honor guards and paratroopers took part in the event, which was organized under the guidance of Commander of Southern Military District Colonel-General Alexander Galkin and was held to honor World War Two veterans and mark the 70th anniversary of the victory over Nazi Germany, according to local media. (Photo by Eduard Korniyenko/Reuters)

A combination picture shows Will Adam, 14, snowboarding down a street on Beacon Hill during a large winter blizzard in Boston, Massachusetts, United States January 27, 2015 (top), and a woman looking at her phone as she walks down the same street June 13, 2015. Outdoor scenes in Boston show local residents enjoying balmy weather amid lush greenery as the summer solstice approaches on 21 June. The very same locations suffered heavy snowstorms last winter, with snow ploughs, skiers and snowboarders battling the drifts. Boston got 275.8 cm of snow over the winter, the most since 1872, when records began. A few months after the snowstorms, Brian Snyder revisited the same places and shot pictures at exactly the same locations. (Photo by Brian Snyder/Reuters)

In this August 3, 2015, photo, residents make their way through floodwaters in Minbu, Magway division, in Myanmar. The Ministry of Social Welfare, Relief and Resettlement said that more than 200,000 people are affected in 11 of the country's 14 states and divisions by flooding. In addition to damage to houses and farmland, infrastructure has been very badly hit, with roads and rail lines cut in many places and telecommunication links broken. (Photo by Hkun Lat/AP Photo)

A Nepalese mother applies make up to her daughter dressed as the living goddess Kumari as they wait for Kumari puja to start at Hanuman Dhoka temple, in Kathmandu, Nepal, Wednesday, September 14, 2016. Girls under the age of nine gathered for the Kumari puja, a tradition of worshiping young prepubescent girls as manifestations of the divine female energy. The ritual holds a strong religious significance in the Newar community that seeks divine blessings to save small girls from diseases and bad luck in the years to come. (Photo by Niranjan Shrestha/AP Photo)

In this Friday, February 5, 2016 picture, Egyptian farmer Ahmed Ayman, 14, rides his trained donkey as he jumps over a barrier in the Nile Delta village of Al-Arid about 150 kilometers north of Cairo, Egypt. He discovered the donkey's talent after she jumped over a small irrigation canal. (Photo by Amr Nabil/AP Photo)

A figure of a skeleton is seen painted in a hallway of the house built underground by Manuel Barrantes in San Isidro de Perez Zeledon, Costa Rica, March 14, 2016. Barrantes started digging through red soil and volcanic rock on his farm 12 years ago to build his subterranean house, between 15 and 63 feet (4.57 and 19.2m) underground. The dwelling, which Barrantes says provides a peaceful and comfortable home for him and his family away from noise pollution and the effects of climate change, now covers about 2,000 square feet (185.8 square metres). (Photo by Juan Carlos Ulate/Reuters)